Add Gravograph IS post processor

OpenNest.Tests/GravographIS/EnvelopeGuardTests.cs

@@ -0,0 +1,165 @@
+using System.Collections.Generic;
+using System.IO;
+using OpenNest.Geometry;
+using OpenNest.Posts.GravographIS;
+
+namespace OpenNest.Tests.GravographIS;
+
+public class EnvelopeGuardTests
+{
+    // 0.610 m / 0.0125 mm/step = 48 800 steps = 24.0157 inches
+    // 1.220 m / 0.0125 mm/step = 97 600 steps = 48.0315 inches
+
+    [Fact]
+    public void NegativeX_FromOrigin_Throws()
+    {
+        // Operator origin is upper-left; quadrant 4 walks right/down. A cut that walks
+        // left of origin in -X must be refused.
+        var polylines = new List<IReadOnlyList<Vector>>
+        {
+            new[] { new Vector(0, 0), new Vector(-1, 0) },
+        };
+
+        var ex = Assert.Throws<System.InvalidOperationException>(() =>
+        {
+            using var ms = new MemoryStream();
+            new GravographISWriter().Write(polylines, ms);
+        });
+
+        Assert.Contains("Polyline 1", ex.Message);
+        Assert.Contains("cut segment", ex.Message);
+        Assert.Contains("segment 1", ex.Message);
+    }
+
+    [Fact]
+    public void PositiveY_FromOrigin_Throws()
+    {
+        // Positive input-Y is above the upper-left origin in quadrant 4.
+        var polylines = new List<IReadOnlyList<Vector>>
+        {
+            new[] { new Vector(0, 0), new Vector(0, 1) },
+        };
+
+        var ex = Assert.Throws<System.InvalidOperationException>(() =>
+        {
+            using var ms = new MemoryStream();
+            new GravographISWriter().Write(polylines, ms);
+        });
+
+        Assert.Contains("Polyline 1", ex.Message);
+    }
+
+    [Fact]
+    public void XExceedsEnvelope_Throws_AndNamesSegment()
+    {
+        // 25" in X is past the 0.610 m (~24.02") envelope.
+        var polylines = new List<IReadOnlyList<Vector>>
+        {
+            new[] { new Vector(0, 0), new Vector(10, 0), new Vector(25, 0) },
+        };
+
+        var ex = Assert.Throws<System.InvalidOperationException>(() =>
+        {
+            using var ms = new MemoryStream();
+            new GravographISWriter().Write(polylines, ms);
+        });
+
+        Assert.Contains("Polyline 1", ex.Message);
+        Assert.Contains("segment 2", ex.Message); // 0→10 ok; 10→25 trips
+        Assert.Contains("25.000\"", ex.Message);
+    }
+
+    [Fact]
+    public void YExceedsEnvelope_Throws()
+    {
+        // -49" in Y is past the 1.220 m (~48.03") envelope.
+        var polylines = new List<IReadOnlyList<Vector>>
+        {
+            new[] { new Vector(0, 0), new Vector(0, -49) },
+        };
+
+        Assert.Throws<System.InvalidOperationException>(() =>
+        {
+            using var ms = new MemoryStream();
+            new GravographISWriter().Write(polylines, ms);
+        });
+    }
+
+    [Fact]
+    public void PenUpTravel_OutsideEnvelope_AlsoThrows_AndIsLabeledTravel()
+    {
+        // Polyline 1 ends in-envelope; the PU travel to polyline 2 leaves it.
+        var polylines = new List<IReadOnlyList<Vector>>
+        {
+            new[] { new Vector(0, 0), new Vector(1, 0) },
+            new[] { new Vector(30, 0), new Vector(30, -1) },
+        };
+
+        var ex = Assert.Throws<System.InvalidOperationException>(() =>
+        {
+            using var ms = new MemoryStream();
+            new GravographISWriter().Write(polylines, ms);
+        });
+
+        Assert.Contains("Polyline 2", ex.Message);
+        Assert.Contains("pen-up travel", ex.Message);
+    }
+
+    [Fact]
+    public void RightAtEnvelopeCorner_IsAllowed()
+    {
+        // Walk to (24", -48") in int16-sized hops (each delta < 16.1"). The
+        // catalog envelope is 24.02" × 48.03", so this lands just inside.
+        var polylines = new List<IReadOnlyList<Vector>>
+        {
+            new[]
+            {
+                new Vector(0, 0),
+                new Vector(8, -16),
+                new Vector(16, -32),
+                new Vector(24, -48),
+            },
+        };
+
+        using var ms = new MemoryStream();
+        new GravographISWriter().Write(polylines, ms); // no throw
+        Assert.True(ms.Length > 0);
+    }
+
+    [Fact]
+    public void EnvelopeGuard_CanBeDisabled_ForOffMachineEncoding()
+    {
+        var polylines = new List<IReadOnlyList<Vector>>
+        {
+            new[] { new Vector(0, 0), new Vector(-5, 0) },
+        };
+
+        var opts = new GravographISWriterOptions { EnvelopeGuardEnabled = false };
+
+        using var ms = new MemoryStream();
+        new GravographISWriter(opts).Write(polylines, ms); // no throw
+        Assert.True(ms.Length > 0);
+    }
+
+    [Fact]
+    public void CustomEnvelope_TightensTheCheck()
+    {
+        // Restrict to 1" × 1" — a 2" line in -Y now overshoots.
+        var polylines = new List<IReadOnlyList<Vector>>
+        {
+            new[] { new Vector(0, 0), new Vector(0, -2) },
+        };
+
+        var opts = new GravographISWriterOptions
+        {
+            WorkEnvelopeXMm = 25.4,
+            WorkEnvelopeYMm = 25.4,
+        };
+
+        Assert.Throws<System.InvalidOperationException>(() =>
+        {
+            using var ms = new MemoryStream();
+            new GravographISWriter(opts).Write(polylines, ms);
+        });
+    }
+}